Carbureter for internal-combustion engines.



w J. F. H. HOWARTH.

CARBURETER FOR INTERNAL COMBUSTION ENGINES.

APPLICATION FILED JUNE 8.1916.

Patented Feb. 5, 1918.

oHNEEEnEEIoK HENRY HOWARTI-I, or MAEEIGKVILLE, NEAR sYnNEY, EW sourn WALES, AUSTRALIA.

CARBUBETER FOR INTERNAL-COMBUSTION ENGINES.

To all whom it may concern:

Be it known that I, JOHN FREDERICK HENRY HOWARTH, a subject of the King of Great Britain and Ireland, residing. at Elystan, 39 Fraser street, Marrickville, nearSydne y, New South Wales, Australia,

have invented certain new anduseful Impliedto a carbureter with a vertical tubular barrel in which a. Venturi choke tube is fitted.

I would have it understood that I do not suggest that there is novelty broadly in the introduction, of additional air. by automatic or manually" controlled means, above the choke tube in a carbureter of the type described. My invention is restricted to particular means for introducing air into the upper part of the carburetor, additional to the air which passes through the Venturi choke tube.

According to this invention vertical grooves are cut in the outer part of the choke tube so as to extend back into the uppermost part of the bore of said tube, and said grooves are put in communication with atmosphere thereby to admit air into the mix- .ing chamber at the top of the choke tube,

and blow the throttle by rotating the choke tube or a part thereof in the casing. vVhen the control is adjusted to close said grooves,

air reaches the mixing chamber only through the throat of the choke tube, but when the control is adjusted so as to bring the grooves into register with the air ports of the casing, more or less air according to the degree of. adjustment is permitted to pass into the mixing chamber at the head of the choke tube and to mingle directly with the fuel mixture which is delivered through the choke tube.

Figure 1 is a sectional elevation of the Specification of Letters Patent.

Patented Feb.5,1918.

Application filed. 'l'une.8,1916. Serial No. 102,388. g l

main part of a carburetor having a vertical tubular barrel embodying my invention;

'Figs. 2' and '3 are horizontal sections re spectively on the lines 2 -2 and 33 in Fig. 1; i Figs. 4: and 6 are fragment vertical sections corresponding with portion of Fig. 1 respectlvelv illustrating two detail varlations in the construction of the grooved choke tube;

Fig. 5 a horizontal seotion'on line 55 f1 in Fig. 4:; Fig. 7 a horlzontal section on line 7--7 Fi 6. As shown in Figs. 1 to 5the Venturi choke tube-is divided into an upper portion A and a lower portion B on a horizontal line C located about the contraction 'of the throat. The upper part A is fixed in the barrel D by screw pins E or otherwise, and the lower part B is rotatable in the casing below the part A, its lower edge being supported on an annular. flange F. G are grooves (three shown) cut vertically in the outer surface of the choke tube, and H are lands inter-- vening between these grooves and made a neat fit for the. barrel D. 'As will be seen inboth these'figures, the grooves G break intof the upper part of the bore of the choke tube, as shown at J. In the construction shown in Fig. 1 they extend through the bottom of the choke tube ring B and communicate at O with the foot box P of the carburetor. In the construction shown in Fig. 4 they stop short of the bottom edge of the choke tube ring B which rests on the annular flange F at the bottom of the casing.

D. K (Figs. 4 and 5) are air ports in the casing D around the location of the choke ring B; these holes form amean of communication between the grooves G in the choke ring'B and outer atmosphere. The ring B is rotatable in the casing D between the fixed part A of the choke tube and the seating flange F by means of an arm L movable through a slot in the casing D; said arm L is connected by rod, flexible wire, or other usual control device to a hand lever (not shown) which is fitted conveniently within the drivers reach.

The lands H are a little wider than the grooves G so that when the choke ring B is turned to bring its lands into alinement with the grooves in the fixed part A of the choke tube communication from outside air to the upper part of the carburcter thIOllgh the grooves is shut off." When however, thering B is turned so as to bring its grooves to a greater or le'ss'extent intoalinement with the grooves in the fixed part A of thechoke ,tube, a proportionate amount of air may 7 pass-through said grooves from the atmos V 'phere'andmix at the top of the choke tube V,

i; f with the fuel mixture therein, which is constituted 'of fuel delivered through the jet Q and air, which haspa ssed through the throat f- "'Air of the chok tube AB and absorbed said phere into the grooves, as shown in Figs. 6c

and but'it is preferable to fix the upper part ofjthe choke tube and to fit its lower portion as anindependent control ring as V shown'in. either Fig. 1 or Fig. 4, the upper part A of the choke tube then forming a a seating against the top surface of the ring B.

QWhat I claim as my invention and desire a to secure by Letters Patent is Inca carbureter,the combination of a turi 'choke tube inclosed in said barrel and having its upper section fixed therein and its lower Section rotatable therein, both, sec- .tions ofthe said choke tube having grooves cut. lengthwise ;1nthe1r outer surfaces, the

grooves extending into the uppermost part of the throat of said tube and being incommunication with the atmosphere at their lower ends, and having lands between them of greater width than said rooves, a means for partially rotating the lower section of the said choke tube, thereby more or less displacinglthe grooves in the two sections of the choke tube, relative to each other and a fuel jet located in said choke tube.

r, 2. In a carbu'reter, the combination of a tubular barrel and a horizontally divided Venturi choke tube inclosed in said" barrel and having its upper section fixed therein and its lower section rotatable therein, both sections of the said choke tube having grooves cut lengthwise in the outer surfaces, the grooves extending into the uppermost part of the throat of said tube and through the lower section thereof 'into the foot box of the carbureter, and having lands between them of greater width than said rooves, a means for partially rotating the ower section of the choke tube thereby more or less displacing the grooves in the two sections of the choke tube relative to each other to admit a variable supplyofair from said foot box into the mixing chamber, and a fuel jet 1 located in said choke tube. tubular'barrel, a horizontally divided Ven- H In testimony whereof I have aflixcd my signature in presence of two witnesses.

JOHN FREDERICK HENRY HOWARTH. Witnesses:

H. G. GAMPBEIL, W. I. DAVIS.

scobiea 01 this patent may be obtained torcfive centseach, by addressing the Commissioner of Patents,

Washington, D. 0. 

